Intraperitoneal infection of birds with Brugia malayi allows subsequent collection of sufficient microfilariae (mf) and adult worms to permit detailed antigen characterization of these stages. In vitro exsheathment of mf allows the collection of sheaths and mf without sheaths. In vitro maintenance of adult worms allows collection of excretions and secretions associated with embryogenesis. Aqueous soluble somatic extracts and detergent solubilized membraneous extracts of the parasitic stages will be prepared. These extracts and ES products will be analyzed by isoelectric focusing (IEF) both preparatively and analytically. The extracts will be labelled with I-125 and minor components detected by autoradiography. Sera from patas and rhesus monkeys experimentally infected with B. malayi are available. Immunoglobulins from these sera and concanavalin A will be coupled to CNBr-activated Sepharose 4B in the preparation of affinity chromatography columns aimed at isolating specific immunogens from the IEF fractions of the parasite preparations. The purified antigens will be evaluated in a number of serodiagnostic tests for Brugian filariasis including immunodiffusion, crossed immunoelectrophoresis and enzyme linked immunosorbant assay. Correlation of the serodiagnostic test results with B. malayi infection kinetics in primates will be accomplished.